Forming sidewall oxide layers for trench isolation

Abstract

A shallow trench isolated integrated circuit may be formed by creating an oxidation enhancing region at the corner between a semiconductor structure surface and the trench. This region may be formed by ion implantation or solid source diffusion in a way which decreases crystallographic defects. As a result, oxidation at the trench may be enhanced without adverse effects on leakage currents. In some embodiments, the impurity laden region is formed first and the trench is etched through the region leaving an impurity laden remnant at the corner between the trench and the structure surface.

What is claimed is:  
     
       1. A semiconductor structure comprising: 
       a trench formed in said semiconductor structure extending through the surface of said semiconductor structure, said trench having a bottom and a sidewall, said sidewall having an upper edge and a lower edge adjacent said bottom; and  
       a region containing oxidation enhancing impurities along the upper edge of said sidewall of said trench, said oxidation enhancing impurities including argon, the remainder of said sidewall of said trench being substantially free of oxidation enhancing impurities, said region exhibiting a degree of implant damage less than that associated with an implant of argon at 10 keV and a dosage of approximately 1×10 15  atoms per square centimeter.